Aortic balloon occlusion cannula

ABSTRACT

An aortic balloon occlusion cannula for the occlusion of the aorta ascendens during cardiac surgery including a cannula containing several lumina that are separated from one another. The cannula carries two dilatable occlusion balloons positioned at a distance from each other, one of the balloons being neighbored to the distal end of the cannula which faces away from the heart and each of the balloons being connected to its own lumen which enables its dilation in independence from the other balloon. The cannula is insertable through the lefthand ventricle of the heart and through the valvula aortae and includes at least one further lumen. The further lumen being connected on the distal side, facing the body, of the distal occlusion balloon to the lumen of the aorta and is adapted to be connected to an extracorporal blood supply device. An additional separate lumen is provided in the cannula and forms a return conduit for liquid and opens on the proximal side of the proximal occlusion balloon.

[0001] The invention concerns an aortic balloon occlusion cannula forthe occlusion of the ascending aorta during cardiac surgery.

[0002] An arteriosclerotically altered ascending aorta represents aproblem in the field of cardiac surgery. It occurs in almost allpatients who suffer from calcification of the coronary vessels or, todifferent degrees, in patients with valvular diseases. It is necessaryto insert an aortic cannula into the ascending aorta in order to connectfor instance a patient, who undergoes a bypass operation, to the extracorporal circulation (heart-lung machine). The blood circulation isseparated from the heart by clamping the ascending aorta towards theheart that is proximal, with a metal clamp, which is attached at rightangles. There is, however, the danger of a detachment of particles orplaques from the wall of the ascending aorta which are transported bythe blood flow especially into the blood vessels of the head andtherefore into the brain. This leads to embolies, which appearclinically often in form of neurological failures (cerebral infarction).

[0003] An aortic balloon occlusion cannula is known from the DE 19 15933 A1. It is used to avoid the risks going along with aortic clampingat right angles during the extracorporeal circulation that is appliedduring cardiac surgeries. It includes an occlusion cannula that can beinserted into a catheter. Its lumen is connected on both sides to adilatable balloon, which allows closing the ascending aorta from theinside by means of a balloon occlusion during the ischemic time withoutan aortic clamping at right angles. A similar aortic occlusion cannulahas also been described in the U.S. Pat. No. 5,334,142, especially inconnection with cardiopulmonary resuscitation. Further embodiments ofocclusion cannulae having two dilatable balloons are disclosed in U.S.Pat. No. 5,458,574 and in EP 1 086 717 A1.

[0004] These balloon cannulae, however, do not solve the problems ofother dangers, which can also lead to a calcified embolie as a result ofan arteriosclerotic ascending aorta.

[0005] In order to be able to suture the vein bypass to the aorta duringa bypass surgery, the aorta has to be clamped with a metal clamp over acertain length in the area of the suture. There is a considerable riskof embolie connected with this therapy. In order to provoke a cardiacarrest, it is also necessary to infuse a cardioplegic substance into theascending aorta. It is also possible that plaques are separated if acardioplegic conduction is inserted especially for this purpose into theascending aorta.

[0006] An object of this invention is to offer a solution to the abovementioned problem and to create an aortic balloon occlusion cannula forthe occlusion of the ascending aorta during surgeries. This aorticballoon occlusion cannula is adapted to reduce the danger of theseparation of calcified plaques from the calcified ascending aorta andto guarantee a careful treatment of the aorta during the surgery.

[0007] To attain this object the balloon occlusion cannula according theinvention shows the characteristics of patent claim 1.

[0008] The new aortic cannula can be placed into the aorta via thelefthand ventricle. Thus the calcified aorta needs not to be opened andsubsequently reclosed. It is just with a arteriosclerotic aortaascendens that suturing of the aorta can be a problem which occasionallynecessitates a partial clamping of this area resulting in an increasedrisk of embolies caused by calcified particles.

[0009] Furthermore, the new aortic cannula permits the clamping of theascending aorta from the inside by means of a dilatable occlusionballoon. In addition, the cannula carries a second occlusion balloonthat is positioned in a certain distance from the first balloon. It isable to separate an area from the perfusion. This area is determined bythe distance between the two balloons. It serves then for the suture ofthe vein bypasses. With this, the dangerous tangential clamping of anaortic area is avoided. In the meantime, the aortic root perfusion canretrogradely be performed by means of a coronary sinus in order toreduce the ischemic time.

[0010] If the aortic root perfusion is retrogradely applied via thecoronary sinus the new cannula can furthermore assume the function ofsucking off the aortic root perfusion. It is one of the advantages ofthe new aortic cannula that, in contrast to the above discussed state ofthe prior art, the occlusion cannula need not be inserted through thecalcified aorta and that, furthermore, the aorta need not be clampedfrom its outside, neither tangentially nor transversely. In addition,neither the tubing for the aortic root perfusion nor a suction tube needto be additionally inserted into the aorta through a separate furtheraccess in the aorta. Finally, the field of the surgical operationremains much clearer as it is the case with the usual technique, for thereason that there are less additional tubings and clamps that tend toencumber the operation field.

[0011] Further embodiments of the new balloon occlusion cannula aresubject of subclaims.

[0012] The illustration shows an example of the subject of theinvention. The following figures show:

[0013]FIG. 1 a balloon cannula according to the invention in situ isschematic illustration

[0014]FIG. 2 the cannula according FIG. 1 cut lengthways along the lineII-II of FIG. 1 in a schematic illustration and

[0015]FIG. 3 the balloon occlusion cannula according to FIG. 1 in anaxial cut, in a side view and in a very simplified illustration.

[0016] The aortic balloon occlusion cannula, which is generally markedby a 1, is to occlude the ascending aorta indicated at 2, during cardiacsurgeries. It contains a cannula tube 3 that is made out of an elasticmaterial. This material enables the introduction of the cannula tube 3,while adapting to the required curvatures, into the ascending aorta 2through a corresponding incision at 4 (FIG. 3) in the lefthand cardiacventricle. When inserting the cannula care must be taken to pass thevalvola aortae 20 as carefully as possible. Therefore, in the beginninga guide wire is placed into the heart and subsequently the cannula isinserted by means of a guide rod that is located in the cannula tube 3and provided with a tapered end. This guide rod defines a lumen for saidguide wire and is removed from the cannula tube 3 when the cannula iscorrectly inserted.

[0017] Cannula tube 3 can also be pre-shaped according to the curvatureof the ascending aorta. Two dilatable occlusion balloons 5 and 6 thatare positioned in a distance from each other, are mounted on the cannulatube 3. The first balloon 5 is positioned at the proximal end of thecannula tube 3, facing the heart, while the other balloon 6 ought to bein a distance of approximately 20 to 30 mm from the balloon 5, closer tothe distal end of the cannula tube 3, facing the body.

[0018] The areas of the outer surface of the cannula tube 3 close to thetwo occlusions balloons 5, 6 are tapered or frustro-conically shaped at50 and 60, respectively, or the cannula tube 3 is provided with afrustro-conical headpiece, which means enhance a smooth passage of thevalvola aortae 20 when the cannula tube 3 is inserted or removed. For asimilar reason the end portions 30 of the cannula tube 3 can be taperedto a point.

[0019] Both occlusions balloons 5, 6 consist of an elastic dilatableplastic, e.g. polyethylene which provides sufficient stiffness andconsistency of shape in order to guarantee a secure closing of theascending aorta 2. The diameter of the two balloons 5, 6 is adapted tothe inner diameter of the ascending aorta 2 and its size is about 35-45mm. The axial width of each of the two occlusion balloons is about 1.5to 2 cm or more. Both occlusion balloons 5, 6 can be positioned on thecannula tube 3 either fixed or in such a way that they are movabletowards each other in order to enable an adaption to the anatomicsituation in each individual case.

[0020] Furthermore the two occlusion balloons can have different axialwidthwise dimensions, the occlusion balloon 6 located close to the endbeing wider than the proximal occlusion balloon 5.

[0021] The cannula 1 contains several separate lumina. They formindependent conduits and can be separated from one another as forinstance indicated schematically in FIG. 2.

[0022] A first lumen 7, indicated in FIG. 3 by a chain doted line, leadsto the first occlusion balloon 5 and permits its dilatation by means ofa suitable dilatation liquid (physiologic salt solution). A second lumen8, shown in FIG. 3 by a double chain dotted line, leads to the secondocclusion balloon 6 and enables its dilatation by means of thecorresponding dilatation liquid.

[0023] Outside of cannula tube 3, suitable fittings for the supply ofdilatation liquid, shut-off valves and controls are assigned to theconduits formed by the lumina 7, 8 in order to dilate the occlusionballoons 5, 6 during the occlusion of the ascending aorta 2, and toreturn them into the non-dilated state. These means and devices are notillustrated in detail. They are well-known.

[0024] A third lumen 9 defines a conduit that opens via openings 140 onthe proximal side, facing the heart, of the occlusion balloon 5. Saidconduit is provided with additional openings 14 in the section betweenthe two occlusion balloons 5 and 6. With the cannula 1 inserted and withan operative valvola aortae 20, liquid can be sucked-off the portion ofthe aorta ascendens 2 which is proximal to the occlusion balloon 5through said openings 14. Furthermore, said conduit permits to suckliquid off the area between the two occlusion balloons 5 and 6 if theocclusion balloon 5 is not dilated or in case of a potential leakage ofthe occlusion balloon 5. The conduit defined by lumen 9 contains ashut-off organ 90 that permits the control of the supply of the heartprotecting solution as required. The internal diameter of the lumen 9 isapproximately 3 mm (to give an approximate size). The liquid rate for aretrograde miocard perfusion is in the order of 500 ml per minute, at amaximum. Additional openings may be added to the third lumen which opento the left ventricle for venting. Alternatively, a separate lumen (notshown) may be included in the cannula that opens to the left ventriclefor venting, if necessary.

[0025] A wider and larger lumen 11 is enclosed by the cannula tube 3. Itis connected to the lumen of the distal part, i.e. the side facing thebody, of the aorta ascendens when the cannula is inserted in the aorta 2over one or more opening(s) 12 in the wall of the cannula 1. Lumen 11forms a blood conduit that is, as indicated schematically in FIG. 1,connected to a heart-lung machine 13 which maintains the circulationextracorporally. The diameter of each of the openings 12 is 10 mm ormore.

[0026] When the new cannula is used—this cannula can also be named as anaortic endoclamping cannula with double balloon technique and integratedcardioplegic cannula—at first the distal occlusion balloon 6 is dilatedafter the insertion of the cannula 1 in the aorta ascendens 2 throughthe incision 4 and the lefthand ventricle.

[0027] With the cannula 1 inserted and with the valvola aortae 20 beingin an operative state a cardioplegic solution can be supplied to theheart through a coronary sinus 21 and a conduit 22 that is in the formof a coronary sinus catheter. Said cardioplegic solution is sucked-ffthrough the conduit defining the lumen 9 while the body circulation issupplied with blood from the heart-lung machine 13 over the lumen 11 andthe opening(s) 12. At this time the anastomoses located close to theheart are sutured.

[0028] Subsequently the second occlusion balloon 5 is dilated, so thatthe aorta ascendens 2 is additionally occluded at this place. Thesection 17 of the aorta ascendens 2 delimited between the two occlusionballoons 5 and 6 is opened and provided with “punched out” anastomoticholes, where upon the anastomoses are sutured. One of them is shown inFIG. 3 at 19. During these proceedings blood is supplied to the heartthrough the coronary sinus catheter 22. The blood is sucked-off throughthe conduit defining the lumen 9.

[0029] Upon the termination of these measures, the two occlusionballoons 5 and 6 are deflated, and the organism is trained to functionwithout the heart-lung machine. The cannula 1 is taken out of the aortaascendens 2 through the lefthand ventricle. The cannula tube 3 shows agenerally straight or, according to the aorta curved section in thesection 17 between the two occlusion balloons 5 and 6. As shown, theadjacent area 18 can lead approximately at right angles from the area17.

1. An aortic balloon occlusion cannula for the occlusion of the aortaascendens during cardiac surgeries comprising: a cannula (1) containingseveral lumina that are separated from one another, said cannulacarrying two dilatable occlusion balloons (5, 6) positioned at adistance from each other, one of said balloons being neighbored to thedistal end of the cannula which faces away from the heart and each ofsaid balloons being connected to its own lumen (7, 8) which enables itsdilatation in independence from the other balloon, said cannula (1)being insertable through the lefthand ventricle of the heart and throughthe valvola aortae (20) and comprising at least one further lumen (11),said further lumen (11) being connected on the distal side, facing thebody, of the distal occlusion balloon (6) to the lumen of the aorta andbeing adapted to be connected to an extracorporal blood supply device(13), and an additional separate lumen (9) provided in said cannula (1)and forming a return conduit for liquid and opening on the proximal sideof the proximal occlusion balloon (5).
 2. The balloon occlusion cannulaaccording to claim 1, characterized in that the cannula (1) is providedin its section between the two occlusion balloons (5, 6) with at leastone opening (14) that opens in this section and that is connected to theadditional lumen (9) in the cannula (1).
 3. The balloon occlusioncannula according to claim 1, characterized in that it comprises acannula tube (3) comprising a first section (17) in the area of the twoocclusion balloons (5, 6) and a second section (18) leading at rightangles therefrom when said cannula (1) is inserted in the aortaascendens (2).
 4. The balloon occlusion cannula according to claim 3,characterized in that the first section (70) of the cannula tube (3) isessentially straight.
 5. The balloon occlusion cannula according toclaim 3, characterized in that the first section (17) of the cannulatube (3) is curved according to the shape of the aorta ascendens (2). 6.The balloon occlusion cannula according to claim 1, characterized inthat the two occlusion balloons (5, 6) are mounted in such a way thatthey are movable with respect to each other in the direction of the axisof the cannula.
 7. The balloon occlusion cannula according to claim 1,characterized that the two occlusion balloons (5, 6) have differentaxial width dimensions.
 8. The balloon occlusion cannula according toclaim 7 characterized in that the distal occlusion balloon (6) has anaxial width that is wider than the axial width of the proximal occlusionballoon (5).
 9. The balloon occlusion cannula according to claim 1,characterized in that it comprises a cannula tube (3) having an outerwall, said outer wall being flared toward its neighboring occlusionballoon in the vicinity of at least one of the two occlusion balloons(5, 6).
 10. The balloon occlusion cannula according to claim 9,characterized in that the frustro-conical flaring is provided on headpiece means that are mounted on the essentially cylindrical cannula tube(3).
 11. The balloon occlusion cannula according to claim 1,characterized in that it comprises a cannula tube (3) that is tapered onits distal end facing the body.
 12. A method of attaching a vein bypassto an ascending aorta of a heart of a body, comprising: providing acannula having two balloons and several lumina that are separated fromone another, wherein the two balloons include a first dilatableocclusion balloon to be located proximal to the heart and a seconddilatable occlusion balloon to be located distally to the heart, andwherein the plurality of separate lumens include a first lumen connectedto the first balloon to enable dilation of the first balloon, a secondlumen connected to the second balloon to enable dilation of the secondballoon independent of the first balloon, and a third lumen that opensto the ascending aorta through an opening on a distal side of the secondballoon; connecting the third lumen to an extracorporal blood supplydevice; inserting the cannula through a left ventricle of the heart andthrough a valvola aortae of the heart; positioning the two balloons inthe ascending aorta such that the two balloons are positioned at adistance from each other along the ascending aorta; dilating the twoballoons; attaching a vein bypass at the ascending aorta between the twoballoons; and deflating the two balloons and removing the cannula fromthe body.
 13. The method of claim 12 wherein the several lumina includea separate lumen in addition to the first, second and third lumens,forming a return conduit for liquid and opening on the proximal side ofthe first balloon.
 14. The method of claim 13, further comprisingapplying a vacuum in the separate lumen to suck off liquid in a portionof the ascending aorta which is on the proximal side of the firstballoon.
 15. The method of claim 13, wherein the separate lumen has aleast one opening that opens between the first and second balloons. 16.The method of claim 15, further comprising applying a vacuum in theseparate lumen to suck off liquid in a portion of the ascending aortawhich is on the proximal side of the first balloon and to suck offliquid between the balloons.
 17. The method of claim 12 furthercomprising supplying cardioplegic solution to the heart.
 18. The methodof claim 17, wherein the cardioplegic solution is supplied through acoronary sinus.
 19. The method of claim 17 wherein the cardioplegicsolution is supplied by an additional separate lumen in the cannula.